Oh yeah, they did build a running system. It was in similar status to the others (eg Dresden's TUDOS) when I made my recommendations. All needed work with QubesOS getting plenty from its dedicated team. Put enough work into something and it will certainly run: see Windows 3.1 on MS-DOS. ;) QubesOS is way better naturally but shows the point that "it runs" doesn't invalidate any design or security claim made about it. Nor is it an excuse for using a bad approach or failing to adapt. Reminds me of programmers with defective code that argue, "But mine ran faster!"
That said, it's usable enough that even I recommend it as an option when strong attackers aren't the opponents. If the attackers are, then it's unlikely to save you and work should be put into the inherently stronger options to get them in better shape. Plus, there's some commercial separation kernels that already run on desktops/laptops etc. one can use. They all use security-focused kernels, user-mode drivers, user-mode networking stacks w/ hardening, trusted boot, I/O MMU, and so on. Not cheap, though, plus a risk of subversion or someone cutting corners. Decisions, decisions. ;)
Truth be told, the whole market (proprietary + FOSS) sucks one way or another. Enemies are probably going to get in if it's a desktop due need to be compatible with much risky garbage. Only the console approaches can be made strong enough with FOSS components right now. Tough trade-offs in ease-of-use, too.
My current recommendation for defending against strong attackers is my old approach: several cheap, hardened machines for physical separation with KVM switch; a guard for sharing between them; sharing done over non-DMA, simple interfaces with simple, easy-to-parse protocols. Additionally, no wireless functionality (even disabled) in them at all. Worked before and still works for less than $1,000 but it ain't pretty or easy to setup.
"Genode provides a "framework" - and basically runs complete systems in separate windows."
Actually, it's a [barely-]usable system differentiated by a resource-management scheme, pluggable microkernels, minimal-TCB native apps, and/or running "complete systems in separate windows." Splitting between microkernel apps and VM's is a proven method that resisted NSA hackers in prior evaluations (eg XTS-400, INTEGRITY-178B). Part that really needs review for risks is their resource-management scheme. However, if proven, it will be advantageous in benefits it offers and especially if microkernel/microhypervisor is enhanced with INTEGRITY RTOS-style resource controls. Malicious apps mostly wouldn't be able to do shit unless there were hardware flaws or problems in the few, trusted components.
Meanwhile, QubesOS runs. So do my Linux LiveCD's and KVM boxes. Malware doesn't hit any of them because the best aren't trying: most targets use Windows or predictable Linux builds. We'll keep using such obfuscation until the [FOSS] strong stuff is ready.
